Mean Girls: Social Stress Models for Female Rodents

Abstract

Social stressors are known to have strong negative impacts on mental health. There is a long history of preclinical social defeat stress studies in rodents focusing on males that has produced important insights into the neural mechanisms that modulate depression- and anxiety-related behavior. Despite these impressive results, a historical weakness of rodent social stress models has been an under-representation of studies in females. This is problematic because rates of depression and anxiety are higher in women versus men. Recently there has been a surge of interest in adapting social stress methods for female rodents. Here we review new rodent models that have investigated numerous facets of social stress in females. The different models have different strengths and weaknesses, with some model systems having stronger ethological validity with other models having better access to molecular tools to manipulate neural circuits. Continued use and refinement of these complementary models will be critical for addressing gaps in understanding the function of neural circuits modulating depression- and anxiety-related behavior in females.

Keywords: Anhedonia; Hamster; Oxytocin; Peromyscus; Sex differences; Vole; Witness defeat.

Figure 1:

Methods for studying social defeat have been developed for several different species. Social stress can be induced via direct physical social defeat or witness defeat protocols. Partner loss in monogamous species is another important form of social stress with translational relevance. Different behavioral assays allow for systematic quantification of the impact of social defeat in different contexts. Social interaction tests assess behaviors in novel or unfamiliar contexts while conditioned defeat and sucrose anhedonia tests are important assessment of behavior in familiar environments.